def write_do(taskhandle, indata, intimeout=0):
'''
Write given data to given task
in taskhandle = Task handle
indata = Samples to write as list of integers
intimeout = Timeout for writing all samples, default 0 = try once
out ErrorText = Error text, None if no errors
'''
errortext = None
#logger.info("Indata: {}".format(indata))
if isinstance(indata, int):
samplecount = 1
datatype = uInt8
data = datatype(indata)
else:
samplecount = len(indata)
datatype = uInt8 * samplecount
data = datatype(*indata)
result = int32()
samples = int32(samplecount)
autostart = bool32(False)
timeout = float64(intimeout)
try:
taskhandle.WriteDigitalU8(samples, autostart,
timeout, DAQmx_Val_GroupByChannel, data,
byref(result), None)
except DAQError as err:
errortext = err
return errortext
def run(self):
while not self._stop_signal.is_set():
# Note to future self: see the comment inside EventNCallback() above
samples_buffer = numpy.zeros((self.task.sample_buffer_size,), dtype=numpy.float64)
try:
self.task.ReadAnalogF64(DAQmx_Val_Auto, self.wait_period, DAQmx_Val_GroupByScanNumber, samples_buffer,
self.task.sample_buffer_size, byref(self.task.samples_read), None)
except DAQError:
pass
self.task.consumer.write((samples_buffer, self.task.samples_read.value))
def EveryNCallback(self):
# Note to future self: do NOT try to "optimize" this but re-using the same array and just
# zeroing it out each time. The writes happen asynchronously and if your zero it out too soon,
# you'll see a whole bunch of 0.0's in the output. If you wanna go down that route, you'll need
# cycler through several arrays and have the code that's actually doing the writing zero them out
# mark them as available to be used by this call. But, honestly, numpy array allocation does not
# appear to be a bottleneck at the moment, so the current solution is "good enough".
samples_buffer = numpy.zeros((self.sample_buffer_size,), dtype=numpy.float64)
self.ReadAnalogF64(DAQmx_Val_Auto, 0.0, DAQmx_Val_GroupByScanNumber, samples_buffer,
self.sample_buffer_size, byref(self.samples_read), None)
self.consumer.write((samples_buffer, self.samples_read.value))
def read_di(taskhandle, intimeout=0):
'''
Read data from given task
in Task handle
Timeout for reading, default 0 = try once
out Read data
'''
value = uInt8()
result = int32()
bytespersample = int32()
samples = int32(1)
readarraysize = uInt32(1)
timeout = float64(intimeout)
taskhandle.ReadDigitalU8(samples, timeout, DAQmx_Val_GroupByScanNumber,
value, readarraysize, byref(result), None)
return value.value
def read_analog_io_RSE(taskhandle, samples, intimeout=100):
'''
Initialize task for reading from analog input port for Voltage measurement
in devport = Device/port e.g. Dev1/ai2
Timeout for reading, default 100
out task = Task handle
'''
datatype = ctypes.c_double * samples
data = datatype()
result = int32()
readarraysize = uInt32(samples)
timeout = float64(intimeout)
taskhandle.ReadAnalogF64(samples, timeout, DAQmx_Val_GroupByChannel, data,
readarraysize, byref(result), None)
#sleep(0.1)
for i in data:
logger.info("Voltage level: {}".format(str(i)))
return repr(data)
def read_analog_io_Diff(taskhandle, samples, intimeout=100):
'''
Read data from given task
in Task handle
Timeout for reading, default 100
out Read data
'''
datatype = ctypes.c_double * samples
data = datatype()
result = int32()
readarraysize = uInt32(samples * 2)
timeout = float64(intimeout)
taskhandle.ReadAnalogF64(samples, timeout, DAQmx_Val_GroupByChannel, data,
readarraysize, byref(result), None)
#sleep(0.1)
for i in data:
logger.info("Voltage level: {}".format(str(i)))
return repr(data)
def EveryNCallback(self):
samples_buffer = numpy.zeros((self.sample_buffer_size,), dtype=numpy.float64)
self.ReadAnalogF64(DAQmx_Val_Auto, 0.0, DAQmx_Val_GroupByScanNumber, samples_buffer,
self.sample_buffer_size, byref(self.samples_read), None)
self.consumer.write((samples_buffer, self.samples_read.value))